Fig 1: Selective Spike/vimentin colocalization in primary cilia. A549 were incubated with Spike S1-Fc, immunostained as in Fig. 8, and monitored by confocal microscopy. Images shown are single sections taken from the lower (bottom section, absence of cilium) or the upper third (top section, presence of cilium) of the cells, as indicated. Graphs show the Manders’ coefficients for Spike overlapping vimentin (Spike >> vim, M1) and vimentin overlapping Spike (Vim >> Spike, M2) at the basal (circles) and top (triangles) cell sections, obtained considering an individual cell (left graph) or the cilium region (right graph), as ROI. Results are average values ± SEM of 12 determinations from three different experiments. ****, p = 0.0001 by unpaired Student’s t-test. Bars, 20 µm.